Core: use span<T> to cut down on array copys

Source/Game/Maps/TransportManager.cs

@@ -203,7 +203,8 @@ namespace Game.Maps
                 {
                     int extra = !keyFrames[i - 1].Teleport ? 1 : 0;
                     Spline spline = new Spline();
-                    spline.Init_Spline(splinePath.Skip(start).ToArray(), i - start + extra, Spline.EvaluationMode.Catmullrom);
+                    Span<Vector3> span = splinePath.ToArray();
+                    spline.Init_Spline(span.Slice(start), i - start + extra, Spline.EvaluationMode.Catmullrom);
                     spline.initLengths();
                     for (int j = start; j < i + extra; ++j)
                     {

Source/Game/Movement/Generators/PathGenerator.cs

@@ -634,9 +634,10 @@ namespace Game.Movement
             uint ns = 0;
             while (ns < nsteerPath)
             {
+                Span<float> span = steerPath;
                 // Stop at Off-Mesh link or when point is further than slop away.
                 if ((steerPathFlags[ns].HasAnyFlag((byte)Detour.dtStraightPathFlags.DT_STRAIGHTPATH_OFFMESH_CONNECTION) ||
-                    !InRangeYZX(steerPath.Skip((int)ns * 3).ToArray(), startPos, minTargetDist, 1000.0f)))
+                    !InRangeYZX(span.Slice((int)ns * 3).ToArray(), startPos, minTargetDist, 1000.0f)))
                     break;
                 ns++;
             }

Source/Game/Movement/Generators/SplineChainMovementGenerator.cs

@@ -45,9 +45,9 @@ namespace Game.Movement
             _msToNext = info.TimeToNext;
         }
 
-        uint SendPathSpline(Unit me, List<Vector3> wp)
+        uint SendPathSpline(Unit me, Span<Vector3> wp)
         {
-            int numWp = wp.Count;
+            int numWp = wp.Length;
             Cypher.Assert(numWp > 1, "Every path must have source & destination");
             MoveSplineInit init = new MoveSplineInit(me);
             if (numWp > 2)
@@ -64,7 +64,7 @@ namespace Game.Movement
             Log.outDebug(LogFilter.Movement, "{0}: Sending spline for {1}.", me.GetGUID().ToString(), index);
 
             SplineChainLink thisLink = _chain[index];
-            uint actualDuration = SendPathSpline(me, thisLink.Points);
+            uint actualDuration = SendPathSpline(me, new Span<Vector3>(thisLink.Points.ToArray()));
             if (actualDuration != thisLink.ExpectedDuration)
             {
                 Log.outDebug(LogFilter.Movement, "{0}: Sent spline for {1}, duration is {2} ms. Expected was {3} ms (delta {4} ms). Adjusting.", me.GetGUID().ToString(), index, actualDuration, thisLink.ExpectedDuration, actualDuration - thisLink.ExpectedDuration);
@@ -90,9 +90,8 @@ namespace Game.Movement
                         Log.outError(LogFilter.Movement, "{0}: Attempted to resume spline chain from invalid resume state ({1}, {2}).", me.GetGUID().ToString(), _nextIndex, _nextFirstWP);
                         _nextFirstWP = (byte)(thisLink.Points.Count - 1);
                     }
-                    List<Vector3> partial = new List<Vector3>();
+                    Span<Vector3> span = thisLink.Points.ToArray();
-                    partial.AddRange(thisLink.Points.Skip(_nextFirstWP - 1).ToArray());
+                    SendPathSpline(me, span.Slice(_nextFirstWP - 1));
-                    SendPathSpline(me, partial);
                     Log.outDebug(LogFilter.Movement, "{0}: Resumed spline chain generator from resume state.", me.GetGUID().ToString());
                     ++_nextIndex;
                     if (_msToNext == 0)

Source/Game/Movement/Spline.cs

@@ -64,12 +64,14 @@ namespace Game.Movement
         }
         void EvaluateCatmullRom(int index, float t, out Vector3 result)
         {
-            C_Evaluate(points.Skip(index - 1).ToArray(), t, s_catmullRomCoeffs, out result);
+            Span<Vector3> span = points;
+            C_Evaluate(span.Slice(index - 1), t, s_catmullRomCoeffs, out result);
         }
         void EvaluateBezier3(int index, float t, out Vector3 result)
         {
             index *= (int)3u;
-            C_Evaluate(points.Skip(index).ToArray(), t, s_Bezier3Coeffs, out result);
+            Span<Vector3> span = points;
+            C_Evaluate(span.Slice(index), t, s_Bezier3Coeffs, out result);
         }
         #endregion
 
@@ -85,7 +87,7 @@ namespace Game.Movement
 
             Init_Spline(controls, count, m);
         }
-        public void Init_Spline(Vector3[] controls, int count, EvaluationMode m)
+        public void Init_Spline(Span<Vector3> controls, int count, EvaluationMode m)
         {
             m_mode = m;
             _cyclic = false;
@@ -120,7 +122,7 @@ namespace Game.Movement
             index_lo = 0;
             index_hi = cyclic ? count : (count - 1);
         }
-        void InitCatmullRom(Vector3[] controls, int count, bool cyclic, int cyclic_point)
+        void InitCatmullRom(Span<Vector3> controls, int count, bool cyclic, int cyclic_point)
         {
             int real_size = count + (cyclic ? (1 + 2) : (1 + 1));
 
@@ -129,7 +131,7 @@ namespace Game.Movement
             int lo_index = 1;
             int high_index = lo_index + count - 1;
 
-            Array.Copy(controls, 0, points, lo_index, count);
+            Array.Copy(controls.ToArray(), 0, points, lo_index, count);
 
             // first and last two indexes are space for special 'virtual points'
             // these points are required for proper C_Evaluate and C_Evaluate_Derivative methtod work
@@ -152,13 +154,13 @@ namespace Game.Movement
             index_lo = lo_index;
             index_hi = high_index + (cyclic ? 1 : 0);
         }
-        void InitBezier3(Vector3[] controls, int count, bool cyclic, int cyclic_point)
+        void InitBezier3(Span<Vector3> controls, int count, bool cyclic, int cyclic_point)
         {
             int c = (int)(count / 3u * 3u);
             int t = (int)(c / 3u);
 
             Array.Resize(ref points, c);
-            Array.Copy(controls, points, c);
+            Array.Copy(controls.ToArray(), points, c);
 
             index_lo = 0;
             index_hi = t - 1;
@@ -190,12 +192,14 @@ namespace Game.Movement
         }
         void EvaluateDerivativeCatmullRom(int index, float t, out Vector3 result)
         {
-            C_Evaluate_Derivative(points.Skip(index - 1).ToArray(), t, s_catmullRomCoeffs, out result);
+            Span<Vector3> span = points;
+            C_Evaluate_Derivative(span.Slice(index - 1), t, s_catmullRomCoeffs, out result);
         }
         void EvaluateDerivativeBezier3(int index, float t, out Vector3 result)
         {
             index *= (int)3u;
-            C_Evaluate_Derivative(points.Skip(index).ToArray(), t, s_Bezier3Coeffs, out result);
+            Span<Vector3> span = points;
+            C_Evaluate_Derivative(span.Slice(index), t, s_Bezier3Coeffs, out result);
         }
         #endregion
         
@@ -221,7 +225,7 @@ namespace Game.Movement
         float SegLengthCatmullRom(int index)
         {
             Vector3 nextPos;
-            var p = points.Skip(index - 1).ToArray();
+            Span<Vector3> p = points.AsSpan(index - 1);
             Vector3 curPos = nextPos = p[1];
 
             int i = 1;
@@ -240,7 +244,7 @@ namespace Game.Movement
             index *= (int)3u;
 
             Vector3 nextPos;
-            var p = points.Skip(index).ToArray();
+            Span<Vector3> p = points.AsSpan(index);
 
             C_Evaluate(p, 0.0f, s_Bezier3Coeffs, out nextPos);
             Vector3 curPos = nextPos;
@@ -297,7 +301,7 @@ namespace Game.Movement
 
         private static readonly Matrix4 s_Bezier3Coeffs = new Matrix4(-1.0f, 3.0f, -3.0f, 1.0f, 3.0f, -6.0f, 3.0f, 0.0f, -3.0f, 3.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f);
 
-        void C_Evaluate(Vector3[] vertice, float t, Matrix4 matr, out Vector3 result)
+        void C_Evaluate(Span<Vector3> vertice, float t, Matrix4 matr, out Vector3 result)
         {
             Vector4 tvec = new Vector4(t * t * t, t * t, t, 1.0f);
             Vector4 weights = (tvec * matr);
@@ -305,7 +309,7 @@ namespace Game.Movement
             result = vertice[0] * weights[0] + vertice[1] * weights[1]
                    + vertice[2] * weights[2] + vertice[3] * weights[3];
         }
-        void C_Evaluate_Derivative(Vector3[] vertice, float t, Matrix4 matr, out Vector3 result)
+        void C_Evaluate_Derivative(Span<Vector3> vertice, float t, Matrix4 matr, out Vector3 result)
         {
             Vector4 tvec = new Vector4(3.0f * t * t, 2.0f * t, 1.0f, 0.0f);
             Vector4 weights = (tvec * matr);

Source/Game/Network/Packets/MovementPackets.cs

@@ -22,6 +22,7 @@ using Game.Entities;
 using Game.Movement;
 using System.Collections.Generic;
 using System.Linq;
+using System;
 
 namespace Game.Network.Packets
 {
@@ -363,7 +364,7 @@ namespace Game.Network.Packets
             else
             {
                 int lastIdx = spline.getPointCount() - 3;
-                Vector3[] realPath = spline.getPoints().Skip(1).ToArray();
+                Span<Vector3> realPath = new Span<Vector3>(spline.getPoints()).Slice(1);
 
                 movementSpline.Points.Add(realPath[lastIdx]);
 
@@ -372,7 +373,7 @@ namespace Game.Network.Packets
                     Vector3 middle = (realPath[0] + realPath[lastIdx]) / 2.0f;
 
                     // first and last points already appended
-                    for (uint i = 1; i < lastIdx; ++i)
+                    for (int i = 1; i < lastIdx; ++i)
                         movementSpline.PackedDeltas.Add(middle - realPath[i]);
                 }
             }

Source/Game/Warden/WardenKeyGeneration.cs

@@ -17,6 +17,7 @@
 
 using System.Linq;
 using System.Security.Cryptography;
+using System;
 
 namespace Game
 {
@@ -25,12 +26,13 @@ namespace Game
         public SHA1Randx(byte[] buff)
         {
             int halfSize = buff.Length / 2;
+            Span<byte> span = buff;
 
             sh = SHA1.Create();
             o1 = sh.ComputeHash(buff, 0, halfSize);
 
             sh = SHA1.Create();
-            o2 = sh.ComputeHash(buff.Skip(halfSize).ToArray(), 0, buff.Length - halfSize);
+            o2 = sh.ComputeHash(span.Slice(halfSize).ToArray(), 0, buff.Length - halfSize);
 
             FillUp();
         }